With laprascopic operations, when for retrieving organ parts in the abdominal cavity or the application of implants a routinely used trocar sleeve is to be replaced by a trocar sleeve or working sleeve with a larger diameter, then there may result the necessity of broadening the puncture channel in the abdominal wall. This is usually carried out with a dilator. With this it is to be observed that during the sleeve change and even before the dilator is inserted, the access to the body cavity may not collapse.
Dilatation systems with a guide rod and a dilatation sleeve are known. Above all they have the shortcoming that the guide rod must be relatively long in order to be able to exchange the trocar sleeves with dilatation sleeves. On applying the trocar sleeve with larger dimensions and with a pushed-on dilatation sleeve over the guide rod, a longer guide rod however is disturbing. One must also take care with the application that the guide rod is not pushed too far distally into the abdominal cavity, since then there arises a danger of injury to the inner organs of the patient. Since a longer guide rod projects proximally quite far out of the trocar sleeve the firm gripping-round of the trocar sleeve is difficult and uncomfortable.
It is the object of the invention to avoid the described shortcomings of existing dilatations systems and to provide a guide rod which on removal of the smaller trocar sleeve remain lying inserted and may serve as a guide when incorporating a larger trocar sleeve or working sleeve.
A guide rod achieving this object is characterised by at least two telescopic rod parts whose ends which are neighboring given the largest possible rod length are lockable and whose extension movement is limited by an abutment. The locking of the rod parts may be effected with a non-positive fit or with a positive fit.
By way of the fact that according to the invention the length of the guide rod may be telescopically changed and the rod parts displaceable to one another in the extended condition may be automatically locked or latched, an exchange of the trocar sleeves may be effected without problem and any inadvertent pushing together may be ruled out.
After pushing on the larger trocar sleeve with the dilatation sleeve, on the proximal end a grip part may be pivoted out of the guide rod axis. By way of this a falling of the guide rod into the body cavity is avoided and a firm gripping-round of the trocar sleeve is possible.
After releasing the locking of the two parts of the guide rod extended to the full length, when the distal rod end meets an organ the guide rod may thus shorten so that no excess pressure is exerted onto an organ and a danger of injury is ruled out.
By way of the fact that the guide rod can be telescoped the guide rod length in the retracted condition may be adapted to the larger trocar sleeve with the dilatation sleeve.
Since according to the invention the distal part of the guide rod at least over a section of its length is provided with a guide groove, along the guide groove in a controlled manner one may incorporate an incision extension with a standard scalpel.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the mention, its operating advantages and specific objects obtained by its use, reference should be made to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.